DIVISIONS COASTAL MODULAR     •     http://www.coastalmodular.com/ The Coastal Modular division of Williams Building Co., Inc. does residential work using modular homes. Modular homes utilize the latest technology to provide a home that is of superior quality at a lower price. BLACKHORSE EXCAVATION     •     http://www.blackhorsedigs.com/ Blackhorse Excavation specializes in septic installations and repairs. As well as septic work, Blackhorse Excavation does selective demolition work and site work. A perfect compliment to any construction company, having all of the site work and septic work done internally allows Williams Building Co., Inc. to greatly reduce the time and cost of your project.